1 /*
2  * videobuf2-core.h - Video Buffer 2 Core Framework
3  *
4  * Copyright (C) 2010 Samsung Electronics
5  *
6  * Author: Pawel Osciak <pawel@osciak.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation.
11  */
12 #ifndef _MEDIA_VIDEOBUF2_CORE_H
13 #define _MEDIA_VIDEOBUF2_CORE_H
14 
15 #include <linux/mm_types.h>
16 #include <linux/mutex.h>
17 #include <linux/poll.h>
18 #include <linux/dma-buf.h>
19 
20 #define VB2_MAX_FRAME	(32)
21 #define VB2_MAX_PLANES	(8)
22 
23 enum vb2_memory {
24 	VB2_MEMORY_UNKNOWN	= 0,
25 	VB2_MEMORY_MMAP		= 1,
26 	VB2_MEMORY_USERPTR	= 2,
27 	VB2_MEMORY_DMABUF	= 4,
28 };
29 
30 struct vb2_alloc_ctx;
31 struct vb2_fileio_data;
32 struct vb2_threadio_data;
33 
34 /**
35  * struct vb2_mem_ops - memory handling/memory allocator operations
36  * @alloc:	allocate video memory and, optionally, allocator private data,
37  *		return NULL on failure or a pointer to allocator private,
38  *		per-buffer data on success; the returned private structure
39  *		will then be passed as buf_priv argument to other ops in this
40  *		structure. Additional gfp_flags to use when allocating the
41  *		are also passed to this operation. These flags are from the
42  *		gfp_flags field of vb2_queue.
43  * @put:	inform the allocator that the buffer will no longer be used;
44  *		usually will result in the allocator freeing the buffer (if
45  *		no other users of this buffer are present); the buf_priv
46  *		argument is the allocator private per-buffer structure
47  *		previously returned from the alloc callback.
48  * @get_dmabuf: acquire userspace memory for a hardware operation; used for
49  *		 DMABUF memory types.
50  * @get_userptr: acquire userspace memory for a hardware operation; used for
51  *		 USERPTR memory types; vaddr is the address passed to the
52  *		 videobuf layer when queuing a video buffer of USERPTR type;
53  *		 should return an allocator private per-buffer structure
54  *		 associated with the buffer on success, NULL on failure;
55  *		 the returned private structure will then be passed as buf_priv
56  *		 argument to other ops in this structure.
57  * @put_userptr: inform the allocator that a USERPTR buffer will no longer
58  *		 be used.
59  * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation;
60  *		   used for DMABUF memory types; alloc_ctx is the alloc context
61  *		   dbuf is the shared dma_buf; returns NULL on failure;
62  *		   allocator private per-buffer structure on success;
63  *		   this needs to be used for further accesses to the buffer.
64  * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
65  *		   buffer is no longer used; the buf_priv argument is the
66  *		   allocator private per-buffer structure previously returned
67  *		   from the attach_dmabuf callback.
68  * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
69  *		of dmabuf is informed that this driver is going to use the
70  *		dmabuf.
71  * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
72  *		  that this driver is done using the dmabuf for now.
73  * @prepare:	called every time the buffer is passed from userspace to the
74  *		driver, useful for cache synchronisation, optional.
75  * @finish:	called every time the buffer is passed back from the driver
76  *		to the userspace, also optional.
77  * @vaddr:	return a kernel virtual address to a given memory buffer
78  *		associated with the passed private structure or NULL if no
79  *		such mapping exists.
80  * @cookie:	return allocator specific cookie for a given memory buffer
81  *		associated with the passed private structure or NULL if not
82  *		available.
83  * @num_users:	return the current number of users of a memory buffer;
84  *		return 1 if the videobuf layer (or actually the driver using
85  *		it) is the only user.
86  * @mmap:	setup a userspace mapping for a given memory buffer under
87  *		the provided virtual memory region.
88  *
89  * Required ops for USERPTR types: get_userptr, put_userptr.
90  * Required ops for MMAP types: alloc, put, num_users, mmap.
91  * Required ops for read/write access types: alloc, put, num_users, vaddr.
92  * Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, map_dmabuf,
93  *				  unmap_dmabuf.
94  */
95 struct vb2_mem_ops {
96 	void		*(*alloc)(void *alloc_ctx, unsigned long size,
97 				  enum dma_data_direction dma_dir,
98 				  gfp_t gfp_flags);
99 	void		(*put)(void *buf_priv);
100 	struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
101 
102 	void		*(*get_userptr)(void *alloc_ctx, unsigned long vaddr,
103 					unsigned long size,
104 					enum dma_data_direction dma_dir);
105 	void		(*put_userptr)(void *buf_priv);
106 
107 	void		(*prepare)(void *buf_priv);
108 	void		(*finish)(void *buf_priv);
109 
110 	void		*(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf,
111 					  unsigned long size,
112 					  enum dma_data_direction dma_dir);
113 	void		(*detach_dmabuf)(void *buf_priv);
114 	int		(*map_dmabuf)(void *buf_priv);
115 	void		(*unmap_dmabuf)(void *buf_priv);
116 
117 	void		*(*vaddr)(void *buf_priv);
118 	void		*(*cookie)(void *buf_priv);
119 
120 	unsigned int	(*num_users)(void *buf_priv);
121 
122 	int		(*mmap)(void *buf_priv, struct vm_area_struct *vma);
123 };
124 
125 /**
126  * struct vb2_plane - plane information
127  * @mem_priv:	private data with this plane
128  * @dbuf:	dma_buf - shared buffer object
129  * @dbuf_mapped:	flag to show whether dbuf is mapped or not
130  * @bytesused:	number of bytes occupied by data in the plane (payload)
131  * @length:	size of this plane (NOT the payload) in bytes
132  * @min_length:	minimum required size of this plane (NOT the payload) in bytes.
133  *		@length is always greater or equal to @min_length.
134  * @offset:	when memory in the associated struct vb2_buffer is
135  *		VB2_MEMORY_MMAP, equals the offset from the start of
136  *		the device memory for this plane (or is a "cookie" that
137  *		should be passed to mmap() called on the video node)
138  * @userptr:	when memory is VB2_MEMORY_USERPTR, a userspace pointer
139  *		pointing to this plane
140  * @fd:		when memory is VB2_MEMORY_DMABUF, a userspace file
141  *		descriptor associated with this plane
142  * @m:		Union with memtype-specific data (@offset, @userptr or
143  *		@fd).
144  * @data_offset:	offset in the plane to the start of data; usually 0,
145  *		unless there is a header in front of the data
146  * Should contain enough information to be able to cover all the fields
147  * of struct v4l2_plane at videodev2.h
148  */
149 struct vb2_plane {
150 	void			*mem_priv;
151 	struct dma_buf		*dbuf;
152 	unsigned int		dbuf_mapped;
153 	unsigned int		bytesused;
154 	unsigned int		length;
155 	unsigned int		min_length;
156 	union {
157 		unsigned int	offset;
158 		unsigned long	userptr;
159 		int		fd;
160 	} m;
161 	unsigned int		data_offset;
162 };
163 
164 /**
165  * enum vb2_io_modes - queue access methods
166  * @VB2_MMAP:		driver supports MMAP with streaming API
167  * @VB2_USERPTR:	driver supports USERPTR with streaming API
168  * @VB2_READ:		driver supports read() style access
169  * @VB2_WRITE:		driver supports write() style access
170  * @VB2_DMABUF:		driver supports DMABUF with streaming API
171  */
172 enum vb2_io_modes {
173 	VB2_MMAP	= (1 << 0),
174 	VB2_USERPTR	= (1 << 1),
175 	VB2_READ	= (1 << 2),
176 	VB2_WRITE	= (1 << 3),
177 	VB2_DMABUF	= (1 << 4),
178 };
179 
180 /**
181  * enum vb2_buffer_state - current video buffer state
182  * @VB2_BUF_STATE_DEQUEUED:	buffer under userspace control
183  * @VB2_BUF_STATE_PREPARING:	buffer is being prepared in videobuf
184  * @VB2_BUF_STATE_PREPARED:	buffer prepared in videobuf and by the driver
185  * @VB2_BUF_STATE_QUEUED:	buffer queued in videobuf, but not in driver
186  * @VB2_BUF_STATE_REQUEUEING:	re-queue a buffer to the driver
187  * @VB2_BUF_STATE_ACTIVE:	buffer queued in driver and possibly used
188  *				in a hardware operation
189  * @VB2_BUF_STATE_DONE:		buffer returned from driver to videobuf, but
190  *				not yet dequeued to userspace
191  * @VB2_BUF_STATE_ERROR:	same as above, but the operation on the buffer
192  *				has ended with an error, which will be reported
193  *				to the userspace when it is dequeued
194  */
195 enum vb2_buffer_state {
196 	VB2_BUF_STATE_DEQUEUED,
197 	VB2_BUF_STATE_PREPARING,
198 	VB2_BUF_STATE_PREPARED,
199 	VB2_BUF_STATE_QUEUED,
200 	VB2_BUF_STATE_REQUEUEING,
201 	VB2_BUF_STATE_ACTIVE,
202 	VB2_BUF_STATE_DONE,
203 	VB2_BUF_STATE_ERROR,
204 };
205 
206 struct vb2_queue;
207 
208 /**
209  * struct vb2_buffer - represents a video buffer
210  * @vb2_queue:		the queue to which this driver belongs
211  * @index:		id number of the buffer
212  * @type:		buffer type
213  * @memory:		the method, in which the actual data is passed
214  * @num_planes:		number of planes in the buffer
215  *			on an internal driver queue
216  * @planes:		private per-plane information; do not change
217  * @timestamp:		frame timestamp in ns
218  */
219 struct vb2_buffer {
220 	struct vb2_queue	*vb2_queue;
221 	unsigned int		index;
222 	unsigned int		type;
223 	unsigned int		memory;
224 	unsigned int		num_planes;
225 	struct vb2_plane	planes[VB2_MAX_PLANES];
226 	u64			timestamp;
227 
228 	/* private: internal use only
229 	 *
230 	 * state:		current buffer state; do not change
231 	 * queued_entry:	entry on the queued buffers list, which holds
232 	 *			all buffers queued from userspace
233 	 * done_entry:		entry on the list that stores all buffers ready
234 	 *			to be dequeued to userspace
235 	 */
236 	enum vb2_buffer_state	state;
237 
238 	struct list_head	queued_entry;
239 	struct list_head	done_entry;
240 #ifdef CONFIG_VIDEO_ADV_DEBUG
241 	/*
242 	 * Counters for how often these buffer-related ops are
243 	 * called. Used to check for unbalanced ops.
244 	 */
245 	u32		cnt_mem_alloc;
246 	u32		cnt_mem_put;
247 	u32		cnt_mem_get_dmabuf;
248 	u32		cnt_mem_get_userptr;
249 	u32		cnt_mem_put_userptr;
250 	u32		cnt_mem_prepare;
251 	u32		cnt_mem_finish;
252 	u32		cnt_mem_attach_dmabuf;
253 	u32		cnt_mem_detach_dmabuf;
254 	u32		cnt_mem_map_dmabuf;
255 	u32		cnt_mem_unmap_dmabuf;
256 	u32		cnt_mem_vaddr;
257 	u32		cnt_mem_cookie;
258 	u32		cnt_mem_num_users;
259 	u32		cnt_mem_mmap;
260 
261 	u32		cnt_buf_init;
262 	u32		cnt_buf_prepare;
263 	u32		cnt_buf_finish;
264 	u32		cnt_buf_cleanup;
265 	u32		cnt_buf_queue;
266 
267 	/* This counts the number of calls to vb2_buffer_done() */
268 	u32		cnt_buf_done;
269 #endif
270 };
271 
272 /**
273  * struct vb2_ops - driver-specific callbacks
274  *
275  * @queue_setup:	called from VIDIOC_REQBUFS and VIDIOC_CREATE_BUFS
276  *			handlers before memory allocation. It can be called
277  *			twice: if the original number of requested buffers
278  *			could not be allocated, then it will be called a
279  *			second time with the actually allocated number of
280  *			buffers to verify if that is OK.
281  *			The driver should return the required number of buffers
282  *			in *num_buffers, the required number of planes per
283  *			buffer in *num_planes, the size of each plane should be
284  *			set in the sizes[] array and optional per-plane
285  *			allocator specific context in the alloc_ctxs[] array.
286  *			When called from VIDIOC_REQBUFS, *num_planes == 0, the
287  *			driver has to use the currently configured format to
288  *			determine the plane sizes and *num_buffers is the total
289  *			number of buffers that are being allocated. When called
290  *			from VIDIOC_CREATE_BUFS, *num_planes != 0 and it
291  *			describes the requested number of planes and sizes[]
292  *			contains the requested plane sizes. If either
293  *			*num_planes or the requested sizes are invalid callback
294  *			must return -EINVAL. In this case *num_buffers are
295  *			being allocated additionally to q->num_buffers.
296  * @wait_prepare:	release any locks taken while calling vb2 functions;
297  *			it is called before an ioctl needs to wait for a new
298  *			buffer to arrive; required to avoid a deadlock in
299  *			blocking access type.
300  * @wait_finish:	reacquire all locks released in the previous callback;
301  *			required to continue operation after sleeping while
302  *			waiting for a new buffer to arrive.
303  * @buf_init:		called once after allocating a buffer (in MMAP case)
304  *			or after acquiring a new USERPTR buffer; drivers may
305  *			perform additional buffer-related initialization;
306  *			initialization failure (return != 0) will prevent
307  *			queue setup from completing successfully; optional.
308  * @buf_prepare:	called every time the buffer is queued from userspace
309  *			and from the VIDIOC_PREPARE_BUF ioctl; drivers may
310  *			perform any initialization required before each
311  *			hardware operation in this callback; drivers can
312  *			access/modify the buffer here as it is still synced for
313  *			the CPU; drivers that support VIDIOC_CREATE_BUFS must
314  *			also validate the buffer size; if an error is returned,
315  *			the buffer will not be queued in driver; optional.
316  * @buf_finish:		called before every dequeue of the buffer back to
317  *			userspace; the buffer is synced for the CPU, so drivers
318  *			can access/modify the buffer contents; drivers may
319  *			perform any operations required before userspace
320  *			accesses the buffer; optional. The buffer state can be
321  *			one of the following: DONE and ERROR occur while
322  *			streaming is in progress, and the PREPARED state occurs
323  *			when the queue has been canceled and all pending
324  *			buffers are being returned to their default DEQUEUED
325  *			state. Typically you only have to do something if the
326  *			state is VB2_BUF_STATE_DONE, since in all other cases
327  *			the buffer contents will be ignored anyway.
328  * @buf_cleanup:	called once before the buffer is freed; drivers may
329  *			perform any additional cleanup; optional.
330  * @start_streaming:	called once to enter 'streaming' state; the driver may
331  *			receive buffers with @buf_queue callback before
332  *			@start_streaming is called; the driver gets the number
333  *			of already queued buffers in count parameter; driver
334  *			can return an error if hardware fails, in that case all
335  *			buffers that have been already given by the @buf_queue
336  *			callback are to be returned by the driver by calling
337  *			@vb2_buffer_done(VB2_BUF_STATE_QUEUED).
338  *			If you need a minimum number of buffers before you can
339  *			start streaming, then set @min_buffers_needed in the
340  *			vb2_queue structure. If that is non-zero then
341  *			start_streaming won't be called until at least that
342  *			many buffers have been queued up by userspace.
343  * @stop_streaming:	called when 'streaming' state must be disabled; driver
344  *			should stop any DMA transactions or wait until they
345  *			finish and give back all buffers it got from buf_queue()
346  *			callback by calling @vb2_buffer_done() with either
347  *			VB2_BUF_STATE_DONE or VB2_BUF_STATE_ERROR; may use
348  *			vb2_wait_for_all_buffers() function
349  * @buf_queue:		passes buffer vb to the driver; driver may start
350  *			hardware operation on this buffer; driver should give
351  *			the buffer back by calling vb2_buffer_done() function;
352  *			it is allways called after calling STREAMON ioctl;
353  *			might be called before start_streaming callback if user
354  *			pre-queued buffers before calling STREAMON.
355  */
356 struct vb2_ops {
357 	int (*queue_setup)(struct vb2_queue *q,
358 			   unsigned int *num_buffers, unsigned int *num_planes,
359 			   unsigned int sizes[], void *alloc_ctxs[]);
360 
361 	void (*wait_prepare)(struct vb2_queue *q);
362 	void (*wait_finish)(struct vb2_queue *q);
363 
364 	int (*buf_init)(struct vb2_buffer *vb);
365 	int (*buf_prepare)(struct vb2_buffer *vb);
366 	void (*buf_finish)(struct vb2_buffer *vb);
367 	void (*buf_cleanup)(struct vb2_buffer *vb);
368 
369 	int (*start_streaming)(struct vb2_queue *q, unsigned int count);
370 	void (*stop_streaming)(struct vb2_queue *q);
371 
372 	void (*buf_queue)(struct vb2_buffer *vb);
373 };
374 
375 /**
376  * struct vb2_ops - driver-specific callbacks
377  *
378  * @verify_planes_array: Verify that a given user space structure contains
379  *			enough planes for the buffer. This is called
380  *			for each dequeued buffer.
381  * @fill_user_buffer:	given a vb2_buffer fill in the userspace structure.
382  *			For V4L2 this is a struct v4l2_buffer.
383  * @fill_vb2_buffer:	given a userspace structure, fill in the vb2_buffer.
384  *			If the userspace structure is invalid, then this op
385  *			will return an error.
386  * @copy_timestamp:	copy the timestamp from a userspace structure to
387  *			the vb2_buffer struct.
388  */
389 struct vb2_buf_ops {
390 	int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
391 	void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
392 	int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb,
393 				struct vb2_plane *planes);
394 	void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
395 };
396 
397 /**
398  * struct vb2_queue - a videobuf queue
399  *
400  * @type:	private buffer type whose content is defined by the vb2-core
401  *		caller. For example, for V4L2, it should match
402  *		the V4L2_BUF_TYPE_* in include/uapi/linux/videodev2.h
403  * @io_modes:	supported io methods (see vb2_io_modes enum)
404  * @fileio_read_once:		report EOF after reading the first buffer
405  * @fileio_write_immediately:	queue buffer after each write() call
406  * @allow_zero_bytesused:	allow bytesused == 0 to be passed to the driver
407  * @quirk_poll_must_check_waiting_for_buffers: Return POLLERR at poll when QBUF
408  *              has not been called. This is a vb1 idiom that has been adopted
409  *              also by vb2.
410  * @lock:	pointer to a mutex that protects the vb2_queue struct. The
411  *		driver can set this to a mutex to let the v4l2 core serialize
412  *		the queuing ioctls. If the driver wants to handle locking
413  *		itself, then this should be set to NULL. This lock is not used
414  *		by the videobuf2 core API.
415  * @owner:	The filehandle that 'owns' the buffers, i.e. the filehandle
416  *		that called reqbufs, create_buffers or started fileio.
417  *		This field is not used by the videobuf2 core API, but it allows
418  *		drivers to easily associate an owner filehandle with the queue.
419  * @ops:	driver-specific callbacks
420  * @mem_ops:	memory allocator specific callbacks
421  * @buf_ops:	callbacks to deliver buffer information
422  *		between user-space and kernel-space
423  * @drv_priv:	driver private data
424  * @buf_struct_size: size of the driver-specific buffer structure;
425  *		"0" indicates the driver doesn't want to use a custom buffer
426  *		structure type. for example, sizeof(struct vb2_v4l2_buffer)
427  *		will be used for v4l2.
428  * @timestamp_flags: Timestamp flags; V4L2_BUF_FLAG_TIMESTAMP_* and
429  *		V4L2_BUF_FLAG_TSTAMP_SRC_*
430  * @gfp_flags:	additional gfp flags used when allocating the buffers.
431  *		Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32
432  *		to force the buffer allocation to a specific memory zone.
433  * @min_buffers_needed: the minimum number of buffers needed before
434  *		start_streaming() can be called. Used when a DMA engine
435  *		cannot be started unless at least this number of buffers
436  *		have been queued into the driver.
437  */
438 /*
439  * Private elements (won't appear at the DocBook):
440  * @mmap_lock:	private mutex used when buffers are allocated/freed/mmapped
441  * @memory:	current memory type used
442  * @bufs:	videobuf buffer structures
443  * @num_buffers: number of allocated/used buffers
444  * @queued_list: list of buffers currently queued from userspace
445  * @queued_count: number of buffers queued and ready for streaming.
446  * @owned_by_drv_count: number of buffers owned by the driver
447  * @done_list:	list of buffers ready to be dequeued to userspace
448  * @done_lock:	lock to protect done_list list
449  * @done_wq:	waitqueue for processes waiting for buffers ready to be dequeued
450  * @alloc_ctx:	memory type/allocator-specific contexts for each plane
451  * @streaming:	current streaming state
452  * @start_streaming_called: start_streaming() was called successfully and we
453  *		started streaming.
454  * @error:	a fatal error occurred on the queue
455  * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
456  *		buffers. Only set for capture queues if qbuf has not yet been
457  *		called since poll() needs to return POLLERR in that situation.
458  * @is_multiplanar: set if buffer type is multiplanar
459  * @is_output:	set if buffer type is output
460  * @copy_timestamp: set if vb2-core should set timestamps
461  * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
462  *		last decoded buffer was already dequeued. Set for capture queues
463  *		when a buffer with the V4L2_BUF_FLAG_LAST is dequeued.
464  * @fileio:	file io emulator internal data, used only if emulator is active
465  * @threadio:	thread io internal data, used only if thread is active
466  */
467 struct vb2_queue {
468 	unsigned int			type;
469 	unsigned int			io_modes;
470 	unsigned			fileio_read_once:1;
471 	unsigned			fileio_write_immediately:1;
472 	unsigned			allow_zero_bytesused:1;
473 	unsigned		   quirk_poll_must_check_waiting_for_buffers:1;
474 
475 	struct mutex			*lock;
476 	void				*owner;
477 
478 	const struct vb2_ops		*ops;
479 	const struct vb2_mem_ops	*mem_ops;
480 	const struct vb2_buf_ops	*buf_ops;
481 
482 	void				*drv_priv;
483 	unsigned int			buf_struct_size;
484 	u32				timestamp_flags;
485 	gfp_t				gfp_flags;
486 	u32				min_buffers_needed;
487 
488 	/* private: internal use only */
489 	struct mutex			mmap_lock;
490 	unsigned int			memory;
491 	struct vb2_buffer		*bufs[VB2_MAX_FRAME];
492 	unsigned int			num_buffers;
493 
494 	struct list_head		queued_list;
495 	unsigned int			queued_count;
496 
497 	atomic_t			owned_by_drv_count;
498 	struct list_head		done_list;
499 	spinlock_t			done_lock;
500 	wait_queue_head_t		done_wq;
501 
502 	void				*alloc_ctx[VB2_MAX_PLANES];
503 
504 	unsigned int			streaming:1;
505 	unsigned int			start_streaming_called:1;
506 	unsigned int			error:1;
507 	unsigned int			waiting_for_buffers:1;
508 	unsigned int			is_multiplanar:1;
509 	unsigned int			is_output:1;
510 	unsigned int			copy_timestamp:1;
511 	unsigned int			last_buffer_dequeued:1;
512 
513 	struct vb2_fileio_data		*fileio;
514 	struct vb2_threadio_data	*threadio;
515 
516 #ifdef CONFIG_VIDEO_ADV_DEBUG
517 	/*
518 	 * Counters for how often these queue-related ops are
519 	 * called. Used to check for unbalanced ops.
520 	 */
521 	u32				cnt_queue_setup;
522 	u32				cnt_wait_prepare;
523 	u32				cnt_wait_finish;
524 	u32				cnt_start_streaming;
525 	u32				cnt_stop_streaming;
526 #endif
527 };
528 
529 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
530 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
531 
532 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
533 void vb2_discard_done(struct vb2_queue *q);
534 int vb2_wait_for_all_buffers(struct vb2_queue *q);
535 
536 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
537 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
538 		unsigned int *count);
539 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
540 		unsigned int *count, unsigned requested_planes,
541 		const unsigned int requested_sizes[]);
542 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
543 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb);
544 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
545 		   bool nonblocking);
546 
547 int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
548 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
549 
550 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
551 		unsigned int index, unsigned int plane, unsigned int flags);
552 
553 int vb2_core_queue_init(struct vb2_queue *q);
554 void vb2_core_queue_release(struct vb2_queue *q);
555 
556 void vb2_queue_error(struct vb2_queue *q);
557 
558 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
559 #ifndef CONFIG_MMU
560 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
561 				    unsigned long addr,
562 				    unsigned long len,
563 				    unsigned long pgoff,
564 				    unsigned long flags);
565 #endif
566 unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file,
567 		poll_table *wait);
568 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
569 		loff_t *ppos, int nonblock);
570 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
571 		loff_t *ppos, int nonblock);
572 
573 /*
574  * vb2_thread_fnc - callback function for use with vb2_thread
575  *
576  * This is called whenever a buffer is dequeued in the thread.
577  */
578 typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv);
579 
580 /**
581  * vb2_thread_start() - start a thread for the given queue.
582  * @q:		videobuf queue
583  * @fnc:	callback function
584  * @priv:	priv pointer passed to the callback function
585  * @thread_name:the name of the thread. This will be prefixed with "vb2-".
586  *
587  * This starts a thread that will queue and dequeue until an error occurs
588  * or @vb2_thread_stop is called.
589  *
590  * This function should not be used for anything else but the videobuf2-dvb
591  * support. If you think you have another good use-case for this, then please
592  * contact the linux-media mailinglist first.
593  */
594 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
595 		     const char *thread_name);
596 
597 /**
598  * vb2_thread_stop() - stop the thread for the given queue.
599  * @q:		videobuf queue
600  */
601 int vb2_thread_stop(struct vb2_queue *q);
602 
603 /**
604  * vb2_is_streaming() - return streaming status of the queue
605  * @q:		videobuf queue
606  */
607 static inline bool vb2_is_streaming(struct vb2_queue *q)
608 {
609 	return q->streaming;
610 }
611 
612 /**
613  * vb2_fileio_is_active() - return true if fileio is active.
614  * @q:		videobuf queue
615  *
616  * This returns true if read() or write() is used to stream the data
617  * as opposed to stream I/O. This is almost never an important distinction,
618  * except in rare cases. One such case is that using read() or write() to
619  * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there
620  * is no way you can pass the field information of each buffer to/from
621  * userspace. A driver that supports this field format should check for
622  * this in the queue_setup op and reject it if this function returns true.
623  */
624 static inline bool vb2_fileio_is_active(struct vb2_queue *q)
625 {
626 	return q->fileio;
627 }
628 
629 /**
630  * vb2_is_busy() - return busy status of the queue
631  * @q:		videobuf queue
632  *
633  * This function checks if queue has any buffers allocated.
634  */
635 static inline bool vb2_is_busy(struct vb2_queue *q)
636 {
637 	return (q->num_buffers > 0);
638 }
639 
640 /**
641  * vb2_get_drv_priv() - return driver private data associated with the queue
642  * @q:		videobuf queue
643  */
644 static inline void *vb2_get_drv_priv(struct vb2_queue *q)
645 {
646 	return q->drv_priv;
647 }
648 
649 /**
650  * vb2_set_plane_payload() - set bytesused for the plane plane_no
651  * @vb:		buffer for which plane payload should be set
652  * @plane_no:	plane number for which payload should be set
653  * @size:	payload in bytes
654  */
655 static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
656 				 unsigned int plane_no, unsigned long size)
657 {
658 	if (plane_no < vb->num_planes)
659 		vb->planes[plane_no].bytesused = size;
660 }
661 
662 /**
663  * vb2_get_plane_payload() - get bytesused for the plane plane_no
664  * @vb:		buffer for which plane payload should be set
665  * @plane_no:	plane number for which payload should be set
666  */
667 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
668 				 unsigned int plane_no)
669 {
670 	if (plane_no < vb->num_planes)
671 		return vb->planes[plane_no].bytesused;
672 	return 0;
673 }
674 
675 /**
676  * vb2_plane_size() - return plane size in bytes
677  * @vb:		buffer for which plane size should be returned
678  * @plane_no:	plane number for which size should be returned
679  */
680 static inline unsigned long
681 vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
682 {
683 	if (plane_no < vb->num_planes)
684 		return vb->planes[plane_no].length;
685 	return 0;
686 }
687 
688 /**
689  * vb2_start_streaming_called() - return streaming status of driver
690  * @q:		videobuf queue
691  */
692 static inline bool vb2_start_streaming_called(struct vb2_queue *q)
693 {
694 	return q->start_streaming_called;
695 }
696 
697 /**
698  * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue
699  * @q:		videobuf queue
700  */
701 static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
702 {
703 	q->last_buffer_dequeued = false;
704 }
705 
706 /*
707  * The following functions are not part of the vb2 core API, but are useful
708  * functions for videobuf2-*.
709  */
710 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb);
711 int vb2_verify_memory_type(struct vb2_queue *q,
712 		enum vb2_memory memory, unsigned int type);
713 #endif /* _MEDIA_VIDEOBUF2_CORE_H */
714